So after a few more hours of fiddling, I got it working. I'm posting here for the benefit of others and to provide an opportunity for those who know a better way to teach me. See the jsFiddle here:
...

I too am struggling to "simply" have a container (panel) size it's height to "fit" it's content. With the caveat that if the content is too big to fit the max possible height (constrained by it's own...